This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Aldolase are ubiquitous enzymes found in all organisms, from prokaryotes to mammals. They have the ability to cleave carbon-carbon bonds. Their role is best known in glycolysis where fructose-1,6-bisphosphate (FBP) aldolase cleaves FBP to dihydroxyacetone-phosphate (DHAP) and glyceraldehy-3-phosphate. The catalytic role assigment to residues has beeen hampered by the lack of genuine reaction intermediate crystallographic structures. The aim of this project is to study the catalytic mechanism of Helicobacter pylori aldolase, which is a class II fructose-1,6-bisphosphate aldolase. We are planning to use subtrate and drugs soaking experiments with native and mutant aldolase crystals to get insight about residues of the active site implicated in the catalysis. As Class II are not found in mammals, these study could lead to the developpement of a new class ot antibiotics.